A PEGylated Tin Porphyrin Complex for Electrocatalytic Proton Reduction:Mechanistic Insights into Main-Group-Element Catalysis

摘要

Electrocatalytic proton reduction to form dihydrogen(H2)is an effective way to store energy in the form of chemical bonds.In this study,we validate the applicability of a main-group-element-based tin porphyrin complex as an effective molecular electrocatalyst for proton reduction.A PEGylated Sn porphyrin complex(SnPEGP)displayed high activity(-4.6 mA cm~(-2)at-1.7 V vs.Fc/Fc~+)and high selectivity(H2 Faradaic efficiency of 94 at-1.7 V vs.Fc/Fc~+)in acetonitrile(MeCN)with trifluoroacetic acid(TFA)as the proton source.The maximum turnover frequency(TOF_(max))for H2 production was obtained as 1099 s~(-1).Spectroelectrochemical analysis,in conjunction with quantum chemical calculations,suggest that proton reduction occurs via an electron-chemical-electron-chemical(ECEC)pathway.This study reveals that the tin porphyrin catalyst serves as a novel platform for investigating molecular electrocatalytic reactions and provides new mechanistic insights into proton reduction.